/* ---------------------------------------------------------------- */
/* This is an example showing the effect of losing significant     */
/* digits.  This program computes sin(x) using an alternating       */
/* infinite series.                                                 */
/* ---------------------------------------------------------------- */

#include  <stdio.h>
#include  <stdlib.h>
#include  <math.h>

#define   EPSILON  1.0e-8

float  MySin(float x)
{
     float  sinx  = 0.0;           /* the sum of the series         */
     float  term  = x;             /* a term of the series          */
     float  sign  = 1.0;           /* sign has values 1, -1, 1, ... */
     float  denom = 1.0;           /* the denominator of a term     */

     while (fabs(term) >= EPSILON) {
          sinx = sinx + sign*term;
          term = term*x/(++denom);
          term = term*x/(++denom);
          sign = -sign;
     }
     return  sinx;
}

void main(void)
{
     float  x;
     float  ans1, ans2;

     printf(" x\t\tMySin\t\tsin(x)\n");
     printf("---\t\t-----\t\t------\n");
     for (x = -30.0; x <= 30.0; x += 5.0) {
          ans1 = MySin(x);
          ans2 = sin(x);
          printf("%f\t%f\t%f\n", x, ans1, ans2);
     }
}